Question: What is the biggest curling iron available?

Answer:  To my knowledge,  the largest curling iron I have seen is the 2 inch Curling Iron.  The 2 inch curling iron is very big.  It makes large large large loose waves if you have long hair.  The 2 inch curling iron may not work in your hair if it is too short.   I have only seen a few brands make the 2 inch curling iron.  Hot Tools, I believe is the best one.  Check it out here.